• Journal of the Korean Chemical Society
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• v.46 no.2
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• pp.157-163
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• 2002

To identify RNA motifs interacting with $tRNA^{Val}$, a SELEX(Systematic Evolution of Ligands by Exponential Enrichment) was applied. Random DNA library which contains a region of ran-domized 48-mer oligonucleotide flanked by conserved sequ ence primers was transcribed into RNA pool using T7 RNA polymerase and RNA aptamers were selected with $tRNA^{Val}$ -immobilized affinity column through 14 rounds of SELEX. Some of the resulting aptamers contained a consensus sequence similar to the sequence in the loop regions of three rRNAs; C43GAAC47 sequence of 5S rRNA, G1491AAGU1495, G1379UUCC1383 sequence of 16S rRNA and C1064UUAG1068, G2110UGUA2114, C2480GACGG2485, A2600CAGU2604 sequence of 23S rRNA. These results suggest that $tRNA^{Val}$ can interact with 5S rRNA, 16S rRNA and 23S rRNA with variety in ribosome.

• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.2005-2011
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• 2012

Nopp140 is a highly phosphorylated protein that resides in the nucleolus of mammalian cell and is involved in the biogenesis of the nucleolus. It interacts with a variety of proteins related to the synthesis and assembly of the ribosome. It also can bind to a ubiquitous protein kinase CK2 that mediates cell growth and prevents apoptosis. We found that Nopp140 is an intrinsically unfolded protein (IUP) lacking stable secondary structures over its entire sequence of 709 residues. We discovered that mitoxantrone, an anticancer agent, was able to enhance the interaction between Nopp140 and CK2 and maintain suppressed activity of CK2. Surface plasma resonance studies on different domains of Nopp140 show that the C-terminal region of Nopp140 is responsible for binding with mitoxantrone. Our results present an interesting example where a small chemical compound binds to an intrinsically unfolded protein (IUP) and enhances protein-protein interactions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.663-669
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• 1999

The purpose of this study was to investigate the effects of vitamin E on the histochemical change of kidney tissue in diabetic rats. Sprague Dawley male rats weighing 100$\pm$10g were randomly assigned to one normal and three STZ induced diabetic groups, which were subdivided into vitamin E free diet(DM 0E group), 40mg vitamin E per kg diet(DM 40E group) and 400mg vitamin E per kg diet(DM 400E group). Vitamin E level of normal group was 40mg per kg diet. Diabetes was exper imentally induced by intravenous injection of 55mg/kg of body weight of streptozotocin(STZ) in citrate buffer(pH 4.3) after 4 weeks feeding of experimental diets. Animals were sacrificed at the 6th day of diabetic states. The contents of thiobarbituric acid(TBARS) in kidney were increased 119%, 84% and 33% in DM 0E, DM 40E and DM 400E groups, respectively, compared to normal group. That of DM 400E group was decreased 39% compared to DM 0E group. Content of 2 microglobulin in urine in DM 0E, DM 40E, and DM 400E groups were increased by 248%, 181%, and 164%, respectively, compared to normal group. The diabetic groups showed the regressive lesion such as renal tubule, intumescence of epithelial cell, vacuolization. The results of the observation through electronic microscope showed the mitochondria shape of proximal tubule epithelial cell, irregular array, increase of ribosome, and irregular arrangement of small villosity, etc. These types of changes appeared severer in DM 0E group than in DM 400E group. These results indicate that the TBARS productions on kdney in STZ induced diabetic rats were increased, consequently those leaded to damage of renal tubule and minuteness structure. But a large quantity vitimin E supplementation was suppressed in TBARS production and improved in peroxidative damage of renal tissue so that relieved degenerative changes of renal tubule epithelial cell.

• Genomics & Informatics
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• v.7 no.4
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• pp.203-207
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• 2009

The target of rapamycin (TOR) signaling pathway conserved from yeast to human plays critical roles in regulation of eukaryotic cell growth. It has been shown that TOR pathway is involved in several cellular processes, including ribosome biogenesis, nutrient response, autophagy and aging. However, due to the functional diversity of TOR pathway, we do not know yet some key effectors of the pathway. To find unknown effectors of TOR signaling pathway, we took advantage of a green fluorescent protein (GFP)-tagged collection of budding yeast Saccharomyces cerevisiae. We analyzed protein abundance changes by measuring the GFP fluorescence intensity of 4156 GFP-tagged yeast strains under inhibition of TOR pathway. Our proteomic analysis argues that 83 proteins are decreased whereas 32 proteins are increased by treatment of rapamycin, a specific inhibitor of TOR complex 1 (TORC1). We found that, among the 115 proteins that show significant changes in protein abundance under rapamycin treatment, 37 proteins also show expression changes in the mRNA levels by more than 2-fold under the same condition. We suggest that the 115 proteins indentified in this study may be directly or indirectly involved in TOR signaling and can serve as candidates for further investigation of the effectors of TOR pathway.

• Journal of Microbiology and Biotechnology
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• v.30 no.9
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• pp.1430-1435
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• 2020

Bacterial cellulose (BC) has outstanding physical and chemical properties, including high crystallinity, moisture retention, and tensile strength. Currently, the major producer of BC is Komagataeibacter xylinus. However, due to limited tools of expression, this host is difficult to engineer metabolically to improve BC productivity. In this study, a regulated expression system for K. xylinus with synthetic ribosome binding site (RBS) was developed and used to engineer a BC biosynthesis pathway. A synthetic RBS library was constructed using green fluorescent protein (GFP) as a reporter, and three synthetic RBSs (R4, R15, and R6) with different strengths were successfully isolated by fluorescence-activated cell sorting (FACS). Using synthetic RBS, we optimized the expression of three homologous genes responsible for BC production, pgm, galU, and ndp, and thereby greatly increased it under both static and shaking culture conditions. The final titer of BC under static and shaking conditions was 5.28 and 3.67 g/l, respectively. Our findings demonstrate that reinforced metabolic flux towards BC through quantitative gene expression represents a practical strategy for the improvement of BC productivity.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.528-533
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• 1995

An antiviral protein (AAP29) with ribosome-inactivating activity was purified and characterized from the leaves of the Amaranthus mangostanus. Purification was accomplished through crude extraction, ammonium sulfate precipitation, S-Sepharose chromatography, gel filtration, CM-Sepharose chromatography and Blue sepharose chromatography. This protein was about 29.2 kDa and strongly basic with the PI value between 9.0 and 9.6, indicating that AAP29 is similar to Type 1 RIP. The AAP29 showed high thermostability without activity toss even after 20 min at $50^{\circ}C$. In cell free system using rabbit reticulocyte lysate, AAP29 inhibited protein synthesis with an $IC_{50}$, of 0.18 nM. This protein also reduced mosaic symptoms of cucumber mosaic virus (CMV) on tobacco leaves. The N-terminal amino acid sequences of the AAP29 are ADLTFTVTKDGTSQSYXTLXNXWRXW and shows no sequence similarity with any known RIPs.

• Korean Journal of Pharmacognosy
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• v.42 no.3
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• pp.246-252
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• 2011

Korean mistletoe Lectin (KML-C) is composed of A and B sub-chain. B chain binds to carbohydrates on cell surface and A chain hinders translation and induces an apoptosis as a RIP (ribosome inactivating protein). KML-C has very strong biological activities, it has seriously limits to use as a cancer therapy or adjuvant because of its toxicity to normal cells. This study is therefore conducted to see if B chain of KML-C might have immunological activity, especially adjuvant activities with less toxicity. We isolated B chain from KML-C using the lactose affinity chromatography, and examined their immunoadjuvant activity. The isolated B-chain did not show any cytotoxicity against tumor cell, RAW264.7, and P388D1 while KML-C had a very strong toxicity. This non-toxic effect was observed also by in-vivo study. Both humoral and cellular immunities were observed ; the antibody titer was increased when the mice were immunized with B-chain used as adjuvant like Freund's adjuvant, indicating that B chain of mistletoe lectin alone might be used for adjuvant; it also increased DTH in cellular immunity. These results suggest that B-chain of KML-C might be used for adjuvant used for the production of antibody or vaccine with less toxicity.

• Korean Journal of Medicinal Crop Science
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• v.15 no.1
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• pp.46-50
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• 2007

Transformed hairy roots were induced from in vitro grown plantlets of Trichosanthes kirilowii by infection with Agrobacterium rhizogenes strain ATCC15834. Transformed hairy roots exhibited active growth with high branching of roots on plant growth regulators-free medium. Cloned line (TR-03) of hairy root was tested for its growth and extracellular protein accumulation in medium under various culture conditions. Among the culture media tested, a full-strength MS medium had a pronounced effect on root biomass and extracelluar protein accumulation in medium. The maximum root biomass (2.4 g DRW/flask) and extracellular total protein contents $(28.3ug/m\ell)$ in medium was obtained at inoculum size of 2 g (FRW) and in MS medium supplemented with 4% sucrose. In addition, the optimal shaking speed for root growth and extracellular protein accumulation in medium were 100 rpm. The total extracellualr protein concentration reached a maximum of $28.3ug/m\ell$ at 4 weeks and decreased thereafter. Protein translation inhibitory activity was observed in culture broths and reached levels of 21.3 unit. These studies demonstrate that the transformed hairy roots can be utilized for the in vitro production of ribosome-inactivating proteins.

• Molecules and Cells
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• v.37 no.1
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• pp.51-57
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• 2014

NOG1 is a nucleolar GTPase that is critical for 60S ribosome biogenesis. Recently, NOG1 was identified as one of the downstream regulators of target of rapamycin (TOR) in yeast. It is reported that TOR is involved in regulating lifespan and fat storage in Caenorhabditis elegans. Here, we show that the nog1 ortholog (T07A9.9: nog-1) in C. elegans regulates growth, development, lifespan, and fat metabolism. A green fluorescence protein (GFP) promoter assay revealed ubiquitous expression of C. elegans nog-1 from the early embryonic to the adult stage. Furthermore, the GFP-tagged NOG-1 protein is localized to the nucleus, whereas the aberrant NOG-1 protein is concentrated in the nucleolus. Functional studies of NOG-1 in C. elegans further revealed that nog-1 knockdown resulted in smaller broodsize, slower growth, increased life span, and more fat storage. Moreover, nog-1 over-expression resulted in decreased life span. Taken together, our data suggest that nog-1 in C. elegans may be an important player in regulating life span and fat storage via the insulin/IGF pathway.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 1997.06a
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• pp.23-49
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• 1997

This is a progress report of rice biotechnology including development of gene transformation system, gene cloning and molecular mapping in rice. The scope of the research was focused on the connection between conventional breeding and biotech-researches. Plant transformation via Agrobacterium or particle bombardment was developed to introduce one or several genes to recommended rice cultivars. Two chimeric genes containing a maize ribosome inactivating protein gene (RIP) and a gerbicide resistant gene (bar) were introduced to Nipponbare, a Japonica cultivar, and transmitted to Korean cultivars. The homozygous progenies of herbicide resistant transgenic plant showed good fertility and agronomic characters. To explore the genetic resourses in rice, over 8,000 cDNA clones from immature rice seed have been isolated and sequenced. About 13% of clones were identified as enzymes related to metabolic pathway. Among them, twenty clones have high homology with genes encoding enzymes in the photorespiratory carbon cycle reaction. Up to now about 100 clones were fully sequenced and registered at EMBL and GenBank. For the mapping of quantitative tarits loci (QTL) and eternal recombinant inbred population with 164 F13 lines (MGRI) was developed from a cross between Milyang 23 and Gihobyeo, Korean rice cultivars. After construction of fully saturated RFLP and AFLP map, quantitative traits using MGRI population were analyzed and integrated into the molecular map. Eighty seven loci were determined with 27 QTL characters including yield and yield components on rice chromosomes. Map based cloning was also tried to isolate semi-dwarf (sd-1) gene in rice. A DNA probe, RG 109, the most tightly linked to sd-1 gene was used to screen from bacterial artifical chromosome (BAC) libraries and five over lapping clones presumably containing sd-1 gene were isolated. Rice genetic database including results of biotech reasearch and classical genetics is provided at Korea Rice Genome Server which is accessible with world wide web (www) browser. The server provides rice cDNA sequences and map informations linked with phenotypic images.